Composting: Making Humus

AUBURN, May 11---The secret ingredient in this recipe is the microlife--bacteria, fungi and other tiny organisms--, that inhabit the surfaces of organic material. Acting as an elaborate food chain within a pile of yard and garden waste, they decompose it as they eat and reproduce. Pile some moist carbon material (dried brown materials such as fallen leaves or straw) either alone or with a much smaller proportion of nitrogen material (moist, green stuff such as vegetable peelings, fresh weeds or grass clippings), and let it happen. With sufficient air the organisms thrive, generating heat within the pile. Eventually, the assembled yard waste is reduced to soft, dark humus.

Encourage even more feverish microbial activity by shredding the material before piling it, turning or stirring the pile more often, or adding more organisms such as red worms.

Here are some sources of humus available to gardeners:

leaves (chopped or shredded)

prunings (grass clippings)

leaf mold (semi-composted leaves)

nonmeat related kitchen waste

sawdust (from nontreated woods)

weeds, dead plants (disease and seed free)

wood chips

bark products

topsoil

mushroom soil

peat moss

manures (dried)

pecan, cocoa hulls

farm crop residues

straw

SOURCE: Dr. Charles Mitchell, Extension Agronomist, Alabama Cooperative Extension System (334) 844-5489, and the National Garden Bureau